No - The issue is there isn't any clear evidence.
We can surmise that the other party was probably going to fast for what they could see ahead, what happened next is pure guess work - maybe a swerve into AD's path to avoid a pedestrian or a loose dog or just lost control or was on the wrong side because they didn't treat the path like road and ride on the left. Poor old AD needs an eye witness and / or the story from the other party to try to piece it all together
Unfortunately, there appears to be no evidence whatsoever that has happened.
We can surmise that it is likely, but supposition is not evidence.
Without either eye-witnesses or CCTV, there is no useful evidence.
OK but I thought that the evidence is reasonable. I am assuming the following "facts": -
1. The perp is identified and has admitted to the collision. He has a broken jaw after all, so may not be in a position to deny any involvement.
2. AD does not suffer from any form of brittle bone disease. Given the list of injuries sustained, we do have clear evidence that the collision happened with considerable force on a shared cycle path which could have very likely contained unpredictable children, dogs, etc.
I suppose the other party could claim that the collision was all AD's fault and she rode in to him. As she doesn't recall the impact, that may be a problem. However, she does say that she was apparently hit from behind. Again if the damage to the bikes and persons concerned, prove that the impact was him riding into AD, then not a problem surely?
The last thing I want to do is give AD false hope (not a lawyer) but at the very least I would have thought the police could question the other party to find out his side of the story.